Site Reliability Engineer - Email Infrastructure

Senior Systems Engineer - Email Reliability (Hybrid SRE)

New York, NY (Hybrid, 3 days in office) 

Top-tier compensation package

Join an elite technology group where systems engineering is a competitive advantage. They treat infrastructure as code, and prioritize reliability above all else, and seeking a Site Reliability Engineer (SRE) or Senior Systems Engineer to architect the next generation of their critical messaging grid. You’ll move beyond managing servers to building the CI/CD pipelines, Observability stacks, and Event-Driven APIs that power the firm's global communication.

The Role 

This is not a standard administration role; it is a Production Engineering position. You will own the reliability and architecture of a complex hybrid stack (Linux/Postfix + Microsoft Exchange). You will partner directly with software developers to decouple legacy monolithic systems and replace them with modern, API-first microservices.

Key Responsibilities:

• Engineer high-availability, stateless Postfix clusters on Linux. Implement modern Infrastructure as Code (IaC) practices using Terraform or Ansible to manage configuration drift and deployment.

• Move beyond ‘up/down’ monitoring. Build sophisticated dashboards (Prometheus, Grafana, ELK) to visualize queue latency, delivery rates, and SMTP performance in real-time.

• Lead the architectural shift from legacy EWS Polling to Event-Driven Graph API Webhooks. Architect the "glue" code in Python or Go that allows internal apps to send mail without touching the backend directly.

• Programmatically manage Sender Reputation. Automate IP warming strategies and enforce DMARC/DKIM/SPF standards across thousands of domains to ensure 99.99% deliverability.

• Manage the edge defense layer (Proofpoint/Mimecast) using policy-as-code where possible, focusing on threat detection and automated remediation pipelines.

Who you are:

• 7+ years of Engineering experience in high-volume messaging or complex infrastructure environments.

• Deep comfort with the Linux kernel, TCP stack tuning, and Postfix/MTA configuration management.

• Proven experience writing production code (Python, Go, or advanced PowerShell Core) to wrap APIs and automate workflows. You don't just run scripts; you build tools.

• Experience managing infrastructure via Terraform, Ansible, or similar config management tools.

• You understand SMTP, TLS, and DNS at the packet level and can debug complex handshake failures in a Wireshark trace.